Submersible pumping systems are often deployed into wells to recover petroleum fluids from subterranean reservoirs. Typically, a submersible pumping system includes a number of components, such as an electric motor coupled to one or more pump assemblies. In many cases, seal sections are placed between pumps and motors. Seal sections are designed to protect intricate internal motor components from harmful wellbore fluids. Seal sections are also used to accommodate the expansion of lubricants from the electric motor and act as a downthrust support during a pumping operation.
Equipment manufacturers have experimented with a number of different types of seal sections. Many seal sections employ an expandable bag or bellows that increases in volume as fluids move through the seal section. Although generally effective, the materials used to manufacture the expandable components are often susceptible to chemical breakdown under the inhospitable downhole environment. Other manufacturers have employed complex labyrinth systems that filter contaminated fluids with gravity-based traps. The labyrinth system often includes a series of ports and chambers that force contaminated fluids to travel upward, thereby allowing gravity to separate heavier contaminated fluids and solids from cleaner, less harmful fluids.
In many installations, modern labyrinth systems effectively filter contaminated fluids moving through the seal section. The success of existing labyrinth systems is, however, dependent on the proper orientation of the seal section with respect to the force of gravity. In non-vertical wells, it is particularly difficult to maintain the proper orientation of labyrinth systems in seal sections. During installation or use, the entire pumping system may rotate, thereby changing the relative positions of the various components within the labyrinth system. If, for example, the labyrinth system becomes inverted or even tipped horizontally, contaminants otherwise trapped by gravity in a proper installation may “fall” into lower portions of the seal section or pumping system. It is to these and other deficiencies in the prior art that the present invention is directed.